U.S. Pat. No. 4,896,149, issued Jan. 23, 1990, to Buzak et al. ("'149 Patent") and assigned to the assignee of the present application, discloses an addressing structure using an ionizable gaseous medium. Such an addressing structure may be used in a system constructed of data storage elements which addresses those data storage elements with the use of an ionizable gas. An example of such a system is a flat panel display, a video camera, or a memory system.
The system disclosed in the '149 Patent has an electrode structure which defines rows of channels, each of which is filled with an ionizable gas. Extending along the base of each of those channels are a row electrode and a reference electrode. The row electrode is electrically driven as a cathode, and the reference electrode is referenced to ground and acts as an anode when the row electrode is electrically driven as a cathode. When a particular row electrode is driven as a cathode, the ionizable gas in the particular channel which contains that row electrode is ionized. Some of the gas atoms are ionized, some are merely excited but not ionized, and the system operates as disclosed in the '149 Patent.
One embodiment of the system disclosed in the '149 Patent is a flat panel display system in which the electric field across an electro-optic material is changed in response to data signals provided over column electrodes. For certain electro-optic materials (for example, liquid crystals) it is necessary to ensure that no long term net DC electric field is applied to the materials; if such a field is applied, the material loses its desired electro-optical properties, or other undesired effects (such as dissociation of a liquid crystal material) can occur. In a flat panel display system this is preferably accomplished by alternating the polarity in immediately succeeding image fields of the data signals applied to the data storage elements ("pixels").
In operating a flat panel display of this type it often happens that pixels do not display the image they are supposed to display. Some such problems are caused by a variety of different cross-talk effects which (together with solutions for mitigating them) are described in U.S. patent application Ser. No. 07/854,145, filed Mar. 19, 1992, for REDUCING CROSS TALK EFFECTS IN ELECTRO-OPTICAL ADDRESSING STRUCTURES, U.S. patent application Ser. No. 07/958,631 for an ADAPTIVE DRIVE WAVEFORM FOR REDUCING CROSSTALK EFFECTS IN ELECTRO-OPTICAL ADDRESSING STRUCTURES, filed Oct. 9, 1992, U.S. Pat. No. 5,414,44 for an ELECTRO-OPTICAL ADDRESSING STRUCTURE HAVING REDUCED SENSITIVITY TO CROSS-TALK, and U.S. Pat. No. 5,400,046 for an ELECTRODE SHUNT IN PLASMA CHANNEL. Each of those applications and patents is assigned to the assignee of the present application.
However, pixels of a flat panel display of the type described in the '149 Patent may also fail to display the image they are supposed to display because pixels in an apparently unpredictable way fail to activate at the proper time or even fail to activate at all. This problem can cause the flat panel display to create an image with incorrect shade or color, inadequate resolution, or annoying flicker.
There is accordingly a need to reduce or eliminate the problem of failure to activate pixels during the operation of a flat panel display using an addressing structure of the type described in the '149 Patent.